Continuously Curved Spar and Method of Manufacturing

Abstract

There is provided in an embodiment an airfoil. The airfoil has one or more fuel containment regions disposed in the airfoil and one or more continuously curved spars extending from a root end of the airfoil toward a tip end of the airfoil. At least one continuously curved spar has a unitary configuration, has one or more continuous curves along the continuously curved spar, and either has a portion forming a structural wall of at least one of the one or more fuel containment regions, or, is internal to the one or more fuel containment regions.

Description

BACKGROUND[0001]1) Field of the Disclosure[0002]The disclosure relates generally to structural spars, and more specifically, to continuously curved structural spars in composite airfoils of air vehicles and methods of manufacturing the same.[0003]2) Description of Related Art[0004]Composite structures are used in a wide variety of applications, including in the manufacture of aircraft, spacecraft, rotorcraft, watercraft, automobiles, and other vehicles and structures, due to their high strength-to-weight ratios, corrosion resistance, and other favorable properties. In aircraft construction, composites structures are used in increasing quantities to form the wings, tail sections, fuselage, and other components.[0005]Known composite airfoils, such as aircraft wings, may utilize upper and lower outer composite wing skin panels, i.e., “skins”, mechanically attached or bonded to an internal frame. The internal frame may typically include reinforcing structures such as spars, ribs, and st...

AI Technical Summary

Benefits of technology

The patent text describes an improved structural spar and a method of manufacturing it. This new spar design and method may be better than existing methods and offer advantages over them.

Problems solved by technology

The use and assembly of such multiple parts and multiple splices may increase the time, complexity, part count, and manual labor required to manufacture the kinked spar, which may, in turn, increase the overall manufacturing costs.

However, the installation, use, and / or removal of such additional mechanical fasteners, clamps, or fixtures may increase the time, complexity, part count, and manual labor required to manufacture the kinked spar, which may, in turn, increase the overall manufacturing costs.

Further, the installation and use of additional mechanical fasteners, clamps, or fixtures that may not be removed after assembly may add weight to the aircraft, which, in turn, may result in an increased fuel requirement for a given flight profile.

This increased fuel requirement may, in turn, result in increased fuel costs.

Finally, the use of numerous fasteners, if made of metal and exposed through the outer composite wing skin panels, may result in an increased risk of a lightning strike to the wing.

In addition, the abrupt change in angle of the one or more discrete kinks in the known kinked spars may result in a significant kick load which must be distributed and resolved by the ribs and wing skins at those kinked areas.

A kick load may cause increased load to the wing skins which may result in wing buckling.

However, such added strength capability may result in increased weight and cost.

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